1. Field of the Invention
The present invention relates to a display device and an inspection method of a position gap, and more particularly to a technique which is effectively applicable to a display device which includes a liquid crystal display panel and a driver IC for driving the liquid crystal display panel.
2. Description of Related Art
Conventionally, as a display device, there has been known a display device which includes a liquid crystal display panel (hereinafter referred to as a liquid crystal display device)
The liquid crystal display panel is, for example, a display panel which seals a liquid crystal material between two substrates which form lines for an image display on transparent substrates such as glass substrates. Here, on one substrate out of these two substrates, for example, elements such as TFTs which apply a voltage to the liquid crystal material are arranged in an array, and color filters and the like are mounted on another substrate.
In assembling the liquid crystal display device, for example, a printed circuit board is arranged on a periphery of the liquid crystal display panel. Then, lines of the printed circuit board and lines of the display panel are connected with lines which are formed on a flexible printed circuit board such as a tape carrier package (TCP), a chip on film (COF) or the like thus establishing an electrical connection with a driver IC for driving the liquid crystal display panel.
As a connection method of the lines of the flexible printed circuit board and the lines of the printed circuit board and a connection method of the lines of the flexible printed circuit board and the lines of the liquid crystal display panel, there has been known a method which performs such a connection using an anisotropic conductive film (ACF).
With respect to the liquid crystal display panel, the large sizing and the higher definition are in progress recently. Accordingly, a pitch between terminals of the liquid crystal display panel is made smaller and hence, in electrically connecting the lines of the liquid crystal display panel and the lines of the flexible printed circuit board, the high positioning accuracy is required.
Accordingly, a connection defect (open defect) attributed to a position gap or short-circuiting defect is liable to be easily generated.
Accordingly, the inspection of the total number of position gaps becomes necessary and hence, there exists a demand for a technique which can facilitate such an inspection.
With respect to the inspection of such position gaps, there has been proposed a method in which an inspection terminal is provided to a liquid crystal display panel side, an inspection lead is provided to a driver IC side, lines are connected with each other, and the electrical conduction between the inspection terminal and the inspection lead is inspected thus determining whether a connection defect attributed to a position gap is generated or not (for example, see Japanese Patent Laid-open Hei 9(1997)-5381 (hereinafter referred to as “patent document 1”).